Method and apparatus for making stepped rims

ABSTRACT

A method and apparatus for manufacturing a stepped rim from a cylindrical ring is provided. The ring is bent outwardly at one end to form a clinch and the opposite end of the ring is indented to form a locking ring groove.

United States Patent 1191 Schriider 1 1 Dec. 18, 1973 METHOD ANDAPPARATUS FOR MAKING [56] References Cited STEPPED RIMS UNITED STATESPATENTS [75] Inventor: Paul SchfiidenI-Iamm/Westfalen, 3,681,962 8/1972Marcovitch 72/87 3,255,518 6/1966 Golata 29/159.l 3,258,833 7/1966Schuttler 29/159.1 Asslgneez ld & C hl n/ stfa n. 3,282,078 11/1966Kaesemeyer... 29/159R Germany 3,388,576 6/1968 Ernestus .1 72/83 [22]Filed: Sept. 16, 1971 FOREIGN PATENTS OR APPLICATIONS '1 2 App] 1 1 170234,826 3/1945 Switzerland ..29/ 1 59.1

. Primary Examiner-Richard J. Herbst [30] Foreign Application PriorityData Attorney-William E. Anderson et a1.

Oct. 28, 1970 Germany P 20 53 005.6

[5 7] ABSTRACT [52] US. Cl. 72/87, 29/159.1 A method and apparatus formanufacturing a stepped [51] Int. Cl. B2ld 22/18 rim from a cylindricalring is provided. The ring is [58] Field of Search. 29/159 R, 159 A,bent outwardly at one end to form clinch and the 29/159.1, 159.02,159.03; 72/80, 81, 82, 86, opposite end of the ring is indented to forma locking 87, 370 ring groove.

4 Claims, 2 Drawing Figures METHOD AND APPARATUS FOR MAKING STEPPED RIMSThis invention relates to a method and apparatus for making stepped rimsfrom flat stock, usually of steel. More specifically, it relates to amethod and apparatus using flat strips cut to the appropriate length.Each strip is first rounded into cylindrical form and the ends arewelded together upon a longitudinal seam to form a ring. A steppedshoulder, a clinch, and a locking ring groove are thereupon formed onthe ring to produce a stepped rim.

Heretofore, stepped rims such as for trucks and other vehicles have beenmade almost exclusively by rounding and welding profiled steel stock.However, this rolled profiled material is substantially more expensivethan flat stock so that the trend has been gradually directed towardusing flat stock for the manufacture of rims.

Furthermore, due to the great variety of different rim widths which aredemanded by the market, the manufacturers of rims have been forced tokeep on stock different stock materials rolled to profile. Suchinventories are not necessary to the same degree when flat material isused to make the rims because such material can be purchased easily andquickly in every desired dimension.

Accordingly, stepped rims have been increasingly made from flat steelstock. Flat steel strips which have been cut to length are bent into around configuration and the end welded together along a longitudinalseam to form a cylindrical ring. The stepped shoulder, the clinch andthe locking ring groove of the rim are then formed successively in anumber of operations on heavy hydraulic bead forming machinesandpresses.

However, this mode of manufacture is subject to several disadvantages.Apart from the greater than average high costs of investment for theequipment for profiling the rims, the rims are always reshaped onhydraulic bead forming machines between a pair of bead rolls. This hasthe consequence of the rims becoming not circular during the processingthereof. Thus, a subsequent expanding and calibrating step is absolutelynecessary in any case. The tolerances to be obtained with suchprocessing are rather wide and do not ensure absolute lack ofeccentricity.

Accordingly, it is an object of the invention to provide a method andapparatus for making stepped rims which is rapid and accurate whilemaintaining very close tolerances, which is automatic and which utilizesa small number of machine units of low cost rather than expensivehydraulic bead forming machines.

Other objects and advantages of the invention will become apparent fromthe following description and the accompanying drawings in which:

FIG. 1 is a partially sectioned side view illustrating the formation ofthe stepped shoulder and of the clinch,

and

ternal chuck. A locking ring groove is then indented on the end of therim remote from the clinch by means of a front pair of rolls and'a rearpair of rolls.

The disclosed apparatus for making stepped rims from flat steel stockhas a machine spindle or shaft which may be hudraulically powered. Theshaft supports both an internal chuck and an external chuck which is ofgreater length than the internal chuck. Between these chucks acylindrical ring blank is clamped. A front roll and a rear roll forforming a stepped shoulder and an upstanding clinch are provided, whichrolls are adapted to be advanced into the openingof the external chuckand the ring. In a second apparatus disposed behind the first apparatus,a machine spindle or shaft has disposed thereon a chuck for clampinglyreceiving the ,end of the workpiece having the clinch thereon, and afront pair of rolls and a rear pair of rolls is provided for indentingthe locking ring groove.

More specifically, as shown in FIG. 1, apparatus for reshaping the rimincluding various features of the invention includes a first spinpressing machine including a spindle or shaft 10 carrying an internalchuck 11 and an external chuck 12. The shaft may be hydraulicallypowered and automatically operated. The external chuck 12 is of greaterlength than the internal chuck 1 l. A rolled cylindrical ringorrim blank13 is disposed between chucks 11 and 12. The blank is expanded at oneend to form a stepped shoulder 14 and a clinch 15 by means of leading orfront roll 16 and a trailing or rear roll 17 which are movable into theopening of the external chuck and the blank toengage the blank. Therolls are so shaped as to cooperate with a shaped inner edge 18 of theexternal chuck 12 which serves as the abutment for forming the steppedshoulder 14 and the clinch 15. The rolls are supported and moved bysupports 19 which may be hydraulically actuated.

As shown in FIG. 2, the apparatus further includes a second spinpressing machine having a rotatable spindle or shaft 19a which carriesan internal chuck 20. A cylindrical workpiece 13 having a steppedshoulder 14 and a clinch 15 which may be preformed as shown in FIG. 1 ispositioned outside the chuck 20 by means of clamping means 26 whichengages the shoulder and clinch. A leading or front pair of rolls 28Aand 28B and a trailing or rear pair of rolls 29A and 29B are positionedadjacent the end of the rim opposite the clinch on movable supports 30which may be hydraulically actuated. As may be seen, one of the leadingrolls 28A is positioned outside of the workpiece 13 and is movabletoward the workpiece while the other of the leading rolls 28B ispositioned beyond the end of the workpiece and is movable partially intoand out of the opening of the workpiece in the directions of the arrow31. The

leading rolls 28A and 28B are so shaped as to cooperate with a shapedouter edge 32 of the internal chuck to first act in cooperation with theabutment 32 and the roll 28A to indent the workpiece. The other of thetrailing rolls 29B is positioned beyond the end of the workpiece and ismovable partially into the opening of the workpiece and alsoperpendicular to the end as shown by the arrows 36 and 37. The trailingrolls 29A and 29B are also mounted on movable supports 30 which may behydraulically actuated. The trailing rolls are so shaped as to cooperatewith each other to bend the end of the workpiece into an uprightposition as shown at 38 to complete formation of a locking groove 39.

In detail, the sequence of operation in the manufacture of a rim is asfollows:

Upon welding of the longitudinal seam and smoothening same, thecylindrical ring 13 or blank is first conveyed, by a conveyor means (notshown) to the center axis of the machine. Thereafter, the ring isautomatically pushed into external chuck 12, e.g., by means of thetailstock, and then clamped between the external chuck l2 and internalchuck 11 by means of a combined clamping and ejecting device (notshown). Upon initiation of rotary movement of the shaft 10, the steppedshoulder 14 and the clinch 15 are formed by means of the two processingrolls l6 and 17 pressing the rim against the abutment 18 in two passes.After stopping the rotary movement, the workpiece 13 is ejected frombetween the chucks 11 and 12 and conveyed to the next machine through atransfer device (not shown). At the same time, a new ring is advancedinto the first machine.

The preformed workpiece 13 is then reversed in position and placed onthe chuck 20 of the second machine with the aid of known devices subjectto the experts choice. The stepped and clinch end of the workpiece isthen clamped on the second machine by the clamping means 26. The twopairs of drawing rolls 28A and 28B and 29A and 29B are advanced towardsthe other end of the workpiece in order to form the locking ring groovein cooperation with the abutment 32 of the chuck 20. In this shapingoperation, the outer rolls 28A and 29A and the other leading roll 28Bfirst are moved onto the workpiece to cooperate with the edge 32 of theinternal chuck and indent the groove and then both rolls 29A and 29Bcooperate to bend the edge thereof into an upright position to completeforming of the locking groove 39.

The edges of the internal chuck 20 and of the external chuck 12 areprovided .with suitable recesses as shown in the Figures for forming therim in the desired shape. The spindles or shafts 10, 19a of bothmachines are rotated for the reshaping operation in known manner byexpedient means. The movements of the rolls 16, 17, 28A, 28B, 29A, 298respectively, are likewise effected in known manner through supportsmoved, e.g., by hydraulic means. The control of the machines, of thetransfer and clamping or ejecting devices and of the roll supports canbe performed manually, or if desired, in an automatic manner byprogrammed control.

The method and the apparatus according to the invention provide someimportant advantages. For example, the expansion of the clinch and theindentation of the locking ring groove can be performed in an automaticprocess by positioning two machine units one behind the other.Withdrawal after a partial processing operation for further processingon another machine is no longer necessary.

Another substantial advantage resides in the reshaping of the workpieceson external or on internal closed chucks. The workpieces are completelysurrounded by the chucks. The reshaping operations per se are performedby means of a pair of rolls, i.e-., a front roll and a rear roll. Thisensures uniform stressing of the material and prevents the workpiecesfrom becoming eccentric. The tolerances to be obtained thereby can bekept to very close limits. The method according to the invention and theapparatus proposed for carrying out such method are particularlysuitable for the production of truck rims although similar shapes couldbe formed without departing from the invention.

Various features of the invention are set forth in the accompanyingclaims.

I claim:

1. A method of manufacturing stepped rims from a flat steel strip,forming the flat steel strip into a cylindrical ring having apredetermined cross-sectional thickness corresponding to the thicknessof the flat steel strip, clamping the ring externally and internallywith force to hold the ring against becoming eccentric during a bendingofa clinch, bending a first end of the ring outwardly while it isclamped to form a clinch and without reducing substantially thecross-sectional thickness of the ring, repositioning the ring and againclamping the ring with external and internal forces to hold the same,indentingthe other end of the ring to form a locking ring groove thereinwhile said ring is clamped, and then bending an edge of the locking ringgroove into an upright position thus completing the formation of thelocking ring groove and thereby providing a ring having a clinch at oneend and a locking ring groove at the other end with a central portionhaving a thickness substantially equal to the thickness of the flatstrip from which the ring was formed.

2. A method in accordance with claim 1 wherein said clinch and saidlocking groove are shaped by a rolling operation.

3. An apparatus for making a stepped rim from a cylindrical ring havinga predetermined cross-sectional thickness comprising an internalrotatable chuck for telescopingly receiving and supporting said ring, anexternal chuck for clamping said ring to said internal chuck to rotatetherewith, a shaped edge on one edge of said internal chuck for shapingone end of said cylindrical ring, a pair of leading rolls for engagingsaid one end of said ring and for deforming the same in cooperation withsaid shaped edge to form a locking ring groove thereon, and a pair oftrailing rolls for engaging the previously deformed portion of said ringand for bending an edge thereof to an upright position to complete saidlocking ring groove, said trailing pairs of rolls also cooperating withsaid shaped edge of said internal chuck while completing the forming ofsaid locking rmg groove.

4. An apparatus according to claim 3 wherein one of said leading rollsand one of. said trailing rolls are positioned circumferentially outwardof said ring and the other of said leading rolls and the other of saidtrailing rolls are positioned to move axially and partially into anopening in the ring.

1. A method of manufacturing stepped rims from a flat steel strip,forming the flat steel strip into a cylindrical ring having apredetermined cross-sectional thickness corresponding to the thicknessof the flat steel strip, clamping the ring externally and internallywith force to hold the ring against becoming eccentric during a bendinGof a clinch, bending a first end of the ring outwardly while it isclamped to form a clinch and without reducing substantially thecross-sectional thickness of the ring, repositioning the ring and againclamping the ring with external and internal forces to hold the same,indenting the other end of the ring to form a locking ring groovetherein while said ring is clamped, and then bending an edge of thelocking ring groove into an upright position thus completing theformation of the locking ring groove and thereby providing a ring havinga clinch at one end and a locking ring groove at the other end with acentral portion having a thickness substantially equal to the thicknessof the flat strip from which the ring was formed.
 2. A method inaccordance with claim 1 wherein said clinch and said locking groove areshaped by a rolling operation.
 3. An apparatus for making a stepped rimfrom a cylindrical ring having a predetermined cross-sectional thicknesscomprising an internal rotatable chuck for telescopingly receiving andsupporting said ring, an external chuck for clamping said ring to saidinternal chuck to rotate therewith, a shaped edge on one edge of saidinternal chuck for shaping one end of said cylindrical ring, a pair ofleading rolls for engaging said one end of said ring and for deformingthe same in cooperation with said shaped edge to form a locking ringgroove thereon, and a pair of trailing rolls for engaging the previouslydeformed portion of said ring and for bending an edge thereof to anupright position to complete said locking ring groove, said trailingpairs of rolls also cooperating with said shaped edge of said internalchuck while completing the forming of said locking ring groove.
 4. Anapparatus according to claim 3 wherein one of said leading rolls and oneof said trailing rolls are positioned circumferentially outward of saidring and the other of said leading rolls and the other of said trailingrolls are positioned to move axially and partially into an opening inthe ring.